summaryrefslogtreecommitdiff
path: root/common/accel-lookup.hpp
diff options
context:
space:
mode:
authora1xd <[email protected]>2021-09-24 02:04:43 -0400
committerGitHub <[email protected]>2021-09-24 02:04:43 -0400
commit2896b8a09ce42e965705c58593b8738adc454f7f (patch)
tree71e4d0cff60b5a1ad11427d78e1f8c7b775e5690 /common/accel-lookup.hpp
parentMerge pull request #107 from a1xd/1.5.0-fix (diff)
parentmake note clearer (diff)
downloadrawaccel-master.tar.xz
rawaccel-master.zip
Merge pull request #108 from a1xd/1.6r2HEADv1.6.0masterdark-mode
v1.6
Diffstat (limited to 'common/accel-lookup.hpp')
-rw-r--r--common/accel-lookup.hpp305
1 files changed, 50 insertions, 255 deletions
diff --git a/common/accel-lookup.hpp b/common/accel-lookup.hpp
index 99f39e9..920df1c 100644
--- a/common/accel-lookup.hpp
+++ b/common/accel-lookup.hpp
@@ -3,31 +3,8 @@
#include "rawaccel-base.hpp"
#include "utility.hpp"
-#include <math.h>
-
namespace rawaccel {
- struct linear_range {
- double start;
- double stop;
- int num;
-
- template <typename Func>
- void for_each(Func fn) const
- {
- double interval = (stop - start) / (num - 1);
- for (int i = 0; i < num; i++) {
- fn(i * interval + start);
- }
- }
-
- int size() const
- {
- return num;
- }
- };
-
-
// represents the range [2^start, 2^stop], with num - 1
// elements linearly spaced between each exponential step
struct fp_rep_range {
@@ -55,252 +32,70 @@ namespace rawaccel {
}
};
- template <typename Lookup>
- struct lut_base {
- enum { capacity = SPACED_LUT_CAPACITY };
- using value_t = float;
-
- template <typename Func>
- void fill(Func fn)
- {
- auto* self = static_cast<Lookup*>(this);
-
- self->range.for_each([&, fn, i = 0](double x) mutable {
- self->data[i++] = static_cast<value_t>(fn(x));
- });
- }
-
- };
-
- struct linear_lut : lut_base<linear_lut> {
- linear_range range;
- bool transfer = false;
- value_t data[capacity] = {};
-
- double operator()(double x) const
- {
- if (x > range.start) {
- double range_dist = range.stop - range.start;
- double idx_f = (x - range.start) * (range.num - 1) / range_dist;
-
- unsigned idx = min(static_cast<int>(idx_f), range.size() - 2);
-
- if (idx < capacity - 1) {
- double y = lerp(data[idx], data[idx + 1], idx_f - idx);
- if (transfer) y /= x;
- return y;
- }
- }
-
- double y = data[0];
- if (transfer) y /= range.start;
- return y;
+ __forceinline
+ constexpr double lerp(double a, double b, double t)
+ {
+ double x = a + t * (b - a);
+ if ((t > 1) == (a < b)) {
+ return maxsd(x, b);
}
+ return minsd(x, b);
+ }
- linear_lut(const spaced_lut_args& args) :
- range({
- args.start,
- args.stop,
- args.num_elements
- }),
- transfer(args.transfer) {}
+ struct lookup {
+ enum { capacity = LUT_POINTS_CAPACITY };
- linear_lut(const accel_args& args) :
- linear_lut(args.spaced_args) {}
- };
+ int size;
+ bool velocity;
- struct binlog_lut : lut_base<binlog_lut> {
- fp_rep_range range;
- double x_start;
- bool transfer = false;
- value_t data[capacity] = {};
+ lookup(const accel_args& args) :
+ size(args.length / 2),
+ velocity(args.gain) {}
- double operator()(double x) const
+ double operator()(double x, const accel_args& args) const
{
- int e = min(ilogb(x), range.stop - 1);
-
- if (e >= range.start) {
- int idx_int_log_part = e - range.start;
- double idx_frac_lin_part = scalbn(x, -e) - 1;
- double idx_f = range.num * (idx_int_log_part + idx_frac_lin_part);
-
- unsigned idx = min(static_cast<int>(idx_f), range.size() - 2);
+ auto* points = reinterpret_cast<const vec2<float>*>(args.data);
+
+ int lo = 0;
+ int hi = size - 2;
+
+ if (x <= 0) return 0;
+
+ if (hi < capacity - 1) {
+
+ while (lo <= hi) {
+ int mid = (lo + hi) / 2;
+ auto p = points[mid];
+
+ if (x < p.x) {
+ hi = mid - 1;
+ }
+ else if (x > p.x) {
+ lo = mid + 1;
+ }
+ else {
+ double y = p.y;
+ if (velocity) y /= x;
+ return y;
+ }
+ }
- if (idx < capacity - 1) {
- double y = lerp(data[idx], data[idx + 1], idx_f - idx);
- if (transfer) y /= x;
+ if (lo > 0) {
+ auto& a = points[lo - 1];
+ auto& b = points[lo];
+ double t = (x - a.x) / (b.x - a.x);
+ double y = lerp(a.y, b.y, t);
+ if (velocity) y /= x;
return y;
}
+
}
- double y = data[0];
- if (transfer) y /= x_start;
+ double y = points[0].y;
+ if (velocity) y /= points[0].x;
return y;
}
-
- binlog_lut(const spaced_lut_args& args) :
- range({
- static_cast<int>(args.start),
- static_cast<int>(args.stop),
- args.num_elements
- }),
- x_start(scalbn(1, range.start)),
- transfer(args.transfer) {}
-
- binlog_lut(const accel_args& args) :
- binlog_lut(args.spaced_args) {}
};
- struct si_pair {
- float slope = 0;
- float intercept = 0;
- };
-
- struct arbitrary_lut_point {
- float applicable_speed = 0;
- si_pair slope_intercept = {};
- };
- struct arbitrary_lut {
- enum { capacity = ARB_LUT_CAPACITY };
-
- fp_rep_range range;
- arbitrary_lut_point data[capacity] = {};
- int log_lookup[capacity] = {};
- double first_point_speed;
- double last_point_speed;
- int last_arbitrary_index;
- int last_log_lookup_index;
- double last_log_lookup_speed;
- double first_log_lookup_speed;
- bool velocity_points;
-
- double operator()(double speed) const
- {
- int index = 0;
- int last_arb_index = last_arbitrary_index;
- int last_log_index = last_log_lookup_index;
-
- if (speed <= 0) return 1;
-
- if (unsigned(last_arb_index) < capacity &&
- unsigned(last_log_index) < capacity &&
- speed > first_point_speed)
- {
- if (speed > last_point_speed)
- {
- index = last_arb_index;
- }
- else if (speed > last_log_lookup_speed)
- {
- int last_log = log_lookup[last_log_index];
- if (unsigned(last_log) >= capacity) return 1;
- index = search_from(last_log, last_arb_index, speed);
- }
- else if (speed < first_log_lookup_speed)
- {
- index = search_from(0, last_arb_index, speed);
- }
- else
- {
- int log_index = get_log_index(speed);
- if (unsigned(log_index) >= capacity) return 1;
- int arbitrary_index = log_lookup[log_index];
- if (arbitrary_index < 0) return 1;
- index = search_from(arbitrary_index, last_arb_index, speed);
- }
-
- }
-
- return apply(index, speed);
- }
-
- int inline get_log_index(double speed) const
- {
- double speed_log = log(speed) - range.start;
- int index = (int)floor(speed_log * range.num);
- return index;
- }
-
- int inline search_from(int index, int last, double speed) const
- {
- do
- {
- index++;
- }
- while (index <= last && data[index].applicable_speed < speed);
-
- return index - 1;
- }
-
- double inline apply(int index, double speed) const
- {
- auto [slope, intercept] = data[index].slope_intercept;
-
- if (velocity_points)
- {
- return slope + intercept / speed;
- }
- else
- {
- return slope * speed + intercept;
- }
- }
-
- void fill(const vec2<float>* points, int length)
- {
- first_point_speed = points[0].x;
- last_arbitrary_index = length - 1;
- // -2 because the last index in the arbitrary array is used for slope-intercept only
- last_point_speed = points[length-2].x;
-
- int start = static_cast<int>(floor(log(first_point_speed)));
- first_log_lookup_speed = exp(start*1.0);
- int end = static_cast<int>(floor(log(last_point_speed)));
- last_log_lookup_speed = exp(end*1.0);
- int num = end > start ? static_cast<int>(capacity / (end - start)) : 1;
- range = fp_rep_range{ start, end, num };
- last_log_lookup_index = end > start ? num * (end - start) - 1 : 0;
-
- vec2<float> current = {0, velocity_points ? 0.0f : 1.0f };
- vec2<float> next;
- int log_index = 0;
- double log_inner_iterator = range.start;
- double log_inner_slice = 1.0 / (range.num * 1.0);
- double log_value = exp(log_inner_iterator);
-
- for (int i = 0; i < length; i++)
- {
- next = points[i];
- double slope = (next.y - current.y) / (next.x - current.x);
- double intercept = next.y - slope * next.x;
- si_pair current_si = {
- static_cast<float>(slope),
- static_cast<float>(intercept)
- };
- arbitrary_lut_point current_lut_point = {
- static_cast<float>(current.x),
- current_si
- };
-
- this->data[i] = current_lut_point;
-
- while (log_value < next.x && log_inner_iterator < end)
- {
- this->log_lookup[log_index] = i;
- log_index++;
- log_inner_iterator += log_inner_slice;
- log_value = exp(log_inner_iterator);
- }
-
- current = next;
- }
- }
-
- arbitrary_lut(const accel_args& args)
- {
- velocity_points = args.arb_args.velocity;
- fill(args.arb_args.data, args.arb_args.length);
- }
- };
}